Role of the particle size of Fe nanoparticles in the capacity of FeF3 batteries
Tsuyoshi Takami,
Keitaro Matsui,
Hiroshi Senoh,
Masahiro Shikano,
Hikari Sakaebe,
Toshiharu Fukunaga
Affiliations
Tsuyoshi Takami
Office of Society-Academia Collaboration for Innovation, Center for Advanced Science & Innovation, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
Keitaro Matsui
Research Institute of Electrochemical Energy (RIECEN), National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
Hiroshi Senoh
Research Institute of Electrochemical Energy (RIECEN), National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
Masahiro Shikano
Research Institute of Electrochemical Energy (RIECEN), National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
Hikari Sakaebe
Research Institute of Electrochemical Energy (RIECEN), National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
Toshiharu Fukunaga
Office of Society-Academia Collaboration for Innovation, Center for Advanced Science & Innovation, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
Fluoride cathode materials that undergo conversion reactions such as FeF3 have attracted increasing interest owing to their high energy density. However, the ability of FeF3 to maintain a high capacity over repeated cycles and the decisive factor dominating conversion reactions have yet to be elucidated. By optimizing the choice of lithium salts and electrolyte solutions, we are able to achieve good capacity retention for an FeF3-based cathode, that is, 4.5-fold enhancement compared with a model electrode (372 mAh/g after 30 cycles). The relationship between the capacity and the particle size of the Fe nanoparticles after discharge is well explained by the order parameter description. These findings provide exciting guidelines for achieving higher capacities for FeF3 batteries.
